Red cell genetic abnormalities, beta-globin gene haplotypes, and APOB polymorphism in the Great Andamanese, a primitive Negrito tribe of Andaman and Nicobar Islands, India

The Great Andamanese are a primitive Negrito tribe of the Andaman and Nicob ar Islands, India, with a total population of 37. We studied 29 individuals from eight families from this population for abnormal hemoglobins, G6PD de ficiency, DNA haplotypes, and apolipoprotein B (APOB, gene) polymorphism. H b E was detected in five individuals, the prevalence of Hb E heterozygotes being 14.3%. One individual had P-thalassemia trait. One female was G6PD de ficient and showed the G6PD Orissa mutation. Haplotype analysis of the beta -globin gene cluster showed that the beta (E) chromosomes were linked to t wo haplotypes (- - - - - + + and + +- + + + +) representing the framework 1 gene, whereas the beta (A) chromosomes showed eight different haplotypic p atterns corresponding to framework 1 and 3 genes. APOB polymorphism analysi s showed that the 631-base-pair (bp) allele was the predominant one with a high homozygosity rate, which could be due to the higher rate of inbreeding in this isolated group. The presence of Hb E and our findings on haplotype analysis supports the hypothesis that the Great Andamanese are reasonably believed to be the surviving representatives of the Negrito race that once flourished in the entire Southeast Asian region in ancient times.